2 Chronicles 32:1 (KJV) After these things, and the establishment thereof, Sennacherib king of Assyria came, and entered into Judah, and encamped against the fenced cities, and thought to win them for himself.

Have a read of 2 Chronicles 32:1-23.
After Hezekiah turned Juda back to the LORD as summarised in “2 Chronicles 31:20-21 (KJV) And thus did Hezekiah throughout all Judah, and wrought that which was good and right and truth before the LORD his God. [21] And in every work that he began in the service of the house of God, and in the law, and in the commandments, to seek his God, he did it with all his heart, and prospered.” You can read more about the reformation in this and previous chapters.

Sennacherib Blasphemes and tries to sow doubt and fear speaking against the LORD God and against GOD’s servant Hezekiah.

What did Hezekiah do? He encouraged everyone to be strong and courageous and trust the in the LORD and then prayed to GOD for deliverance.
“2 Chronicles 32:7-8 (KJV) Be strong and courageous, be not afraid nor dismayed for the king of Assyria, nor for all the multitude that is with him: for there be more with us than with him: [8] With him is an arm of flesh; but with us is the LORD our God to help us, and to fight our battles. And the people rested themselves upon the words of Hezekiah king of Judah.”

“2 Chronicles 32:20 (NKJV) Now because of this King Hezekiah and the prophet Isaiah, the son of Amoz, prayed and cried out to heaven.”

In answer to the prayers the LORD sent an angel to deal with the opposition.

There are many things we can learn from this. One o them is that often when we turn to or turn back to Jesus Christ the enemy will try to come in trying to undo it all by causing trouble. But when we fear, trust and keep our focus on the LORD and do not give in but pray the LORD will in the end bring victory. “Isaiah 59:19 (KJV) So shall they fear the name of the LORD from the west, and his glory from the rising of the sun. When the enemy shall come in like a flood, the Spirit of the LORD shall lift up a standard against him.”

If we turn to GOD or start doing more of what He shows us that we can expect trouble and should not be surprised by it. Therefore let us all be encouraged that GOD is ultimately in control and we do not need to fear, doubt, panic, etc. but instead call on our GOD to deliver us. “Romans 8:31-39 (KJV) What shall we then say to these things? If God be for us, who can be against us? [32] He that spared not his own Son, but delivered him up for us all, how shall he not with him also freely give us all things? [33] Who shall lay any thing to the charge of God’s elect? It is God that justifieth. [34] Who is he that condemneth? It is Christ that died, yea rather, that is risen again, who is even at the right hand of God, who also maketh intercession for us. [35] Who shall separate us from the love of Christ? shall tribulation, or distress, or persecution, or famine, or nakedness, or peril, or sword? [36] As it is written, For thy sake we are killed all the day long; we are accounted as sheep for the slaughter. [37] Nay, in all these things we are more than conquerors through him that loved us. [38] For I am persuaded, that neither death, nor life, nor angels, nor principalities, nor powers, nor things present, nor things to come, [39] Nor height, nor depth, nor any other creature, shall be able to separate us from the love of God, which is in Christ Jesus our Lord.”